Principal axis may refer to:
- Principal axis (mechanics)
- Aircraft principal axes
- Principal axis theorem
- Principal axes of a Matrix
- Principal axis (crystallography)
- Optical axis
Famous quotes containing the words principal and/or axis:
“The principal difference between love and hate is that love is a irradiation, and hate is a concentration. Love makes everything lovely; hate concentrates itself on the object of its hatred.”
—Sydney J. Harris (b. 1917)
“I make this direct statement to the American people that there is far less chance of the United States getting into war, if we do all we can now to support the nations defending themselves against attack by the Axis than if we acquiesce in their defeat, submit tamely to an Axis victory, and wait our turn to be the object of attack in another war later on.”
—Franklin D. Roosevelt (1882–1945)